Last November, we announced that we began allowing advertisers to create image link ads on Facebook with aspect ratio up to 1:1 (square) using the Marketing API. Starting April 30, new ads on the latest API version will not be able to leverage the 191x100 crop spec. Previous API versions will still support the legacy 191x100 crop spec, but will be phased out as those versions expire. This change is specific to Facebook, as we currently already support up to a 1:1 aspect ratio for Instagram image link ads. This means the following:

The field use_flexible_image_aspect_ratio will be defaulted to true. When use_flexible_image_aspect_ratio is set to true, you can leverage any aspect ratio between 1.91:1 and 1:1 without cropping the image. Note that any image taller than 1:1 or wider than 1.91:1 will still be cropped.

The 191x100 crop spec will no longer be available in the newest Ads API version. The recommended crop key will be 100x100.

From initial testing, we saw that 1:1 image link ads showed significant improvement in click-through rate and conversion rate, when compared to the original 1.91:1 (landscape) aspect ratio. Moving forward, we recommend that advertisers leverage 1:1 (square) image creatives for their image link ads. This should also provide more flexibility to use the same creative across Facebook and Instagram placements.

The following placements on Facebook will render the taller image as-is:

Mobile Feed (Android and iOS) app versions 194 and up

Desktop Feed

Desktop Right Hand Column

FBLite

Marketplace Mobile

Audience Network

The following placements will see padded landscape images (1.91:1):

Mobile Feed (Android and iOS) app versions 193 and below

Ads in Instant Article

Messenger Ads

For Facebook Stories and Ad Breaks, the original image will be used for rendering and padded on top and bottom. The cropped images from Ads Manager will not be used.

The following ads support single images (i.e. will allow taller images):